Ke-Rong Jin serves as the captain of the first regiment of the Manchukuo Imperial Guard, a position of considerable authority within the regime of the puppet emperor Puyi. He is widely known by his epithet, the Fist Xia of Hebei, a title that speaks to his reputation as a formidable and chivalrous martial artist from that region.

Jin is a dedicated master of Bājíquán, a real-world martial art known as the Fist of the Eight Extremes, which he combines with the unorthodox use of a metal fan as his primary weapon. His past is marked by a significant encounter with Kenshiro Kasumi that took place years ago in Shanghai. At that time, Jin was working as a bodyguard for a Jewish financial group when he and Kenshiro fought. The duel concluded as a draw, but Jin felt deeply insulted because he believed Kenshiro held back, refusing to use the lethal techniques of Hokuto Shinken against him. This perceived slight left a lasting scar on Jin, not just physically on his chest, but also on his pride.

Driven by a burning desire for a true rematch, Jin resorts to extreme measures to lure his rival out of hiding. He captures and tortures Li Yongjian, a friend of Kenshiro, using him as bait. Jin explains his past grudge to the captive Li, revealing the depth of his obsession with proving himself against Kenshiro’s full power. When Kenshiro finally arrives to confront him, Jin gets the rematch he has been seeking. In this second battle, Kenshiro does not hold back and uses Hokuto Shinken, defeating Jin with relative ease. Despite his defeat, Jin demonstrates his personal code of honor by begging to be killed rather than live with the shame of another loss. However, Kenshiro refuses to deliver the killing blow, recognizing Jin as a noble man and leaving him alive as a sign of respect. This encounter solidifies Jin's role as a significant early antagonist whose primary narrative function is to demonstrate the overwhelming power of Hokuto Shinken while also showcasing its wielder's capacity for mercy and judgment.